Microstructure Construction and Wetting Mechanism of Tooth Groove Surfaces
With the increasing number of surgeries and medical procedures,surgical instruments are frequently used and exposed to various environments probably leading to rustiness and wear. In addition,the blood and tissue residues in surgical instruments are difficult to be cleaned,which results in the aggregation of bacteria and microorganisms,causing infection at patients' wound. A secondary microstructure at the mouth of hemostatic forceps can change the forceps surface wettability,inhibit blood residue,reduce bacterial adhesion,and improve cleaning efficiency of the instrument. Therefore,constructing super-hydrophobic surfaces on surgical instruments is of great significance for research and industry.In this study,a submillimeter/micron-scale multilevel-structured surface was prepared on the surface of a 3Cr13 stainless steel using wire electrical discharge machining (WEDM) composite nanosecond laser ablation. A self-assembled 1H,1H,2H,2H-perflfluorodecyltriethoxysilane (PFDS) coating was further applied to downgrade the surface energy. The surface morphology and wettability of the samples were characterized and tested with a scanning electron microscope and a contact angle meter. Micron grooves were uniformly distributed on the inclined surface of submillimeter grooves,and the shapes of grooves at different heights were consistent,with directions parallel to the grooves. The effect of the surface wettability of the structure was investigated at both submillimeter and micron scales. The microgrooves on the surfaces of the samples changed the contact state of the droplet from the Wenzel model to the Cassie-Baxter model,which effectively improved the rolling performance of the droplet. A surface tension meter was used to evaluate the adhesion force curve of the droplet on the surface of the sample. The maximum adhesion force of the tooth groove array sample was 164.1 μN,whereas the minimum adhesion force was 123.5 μN. The adhesion forces of the samples with multilevel structure were 77.2,47,and 24.1 μN. There was a strong positive correlation between the rolling angle of the specimens and adhesion force. The adhesion force and rolling angle of the multilevel-structured sample with a vertex angle of 60° were the largest,whereas the adhesion force and rolling angle of the multilevel-structured sample with a vertex angle of 120° were the smallest.The results of this study revealed the solid-liquid adhesion mechanism on the tooth groove surface,which had important theoretical and practical value for the design and manufacture of new surgical medical devices. The effects of the sub-millimeter tooth groove apex angle and tooth groove depth on wettability were studied,and the influence of microgrooves on the contact state between the droplet and sample was studied,providing insight into complex planar hydrophobic mechanisms. The results showed that the contact area between the droplet and the surface changed from an integral contact area to multiple discontinuous areas of micro-grooves,which increased the three-phase contact line between the droplet and the surface. The Wenzel model contact between the droplet and sample changed to the Cassie-Baxter model contact and remained stable. The multilevel structure reduced the surface adhesion. Compared with the tooth groove array surface with a similar vertex angle,the adhesion of the 120° multilevel structured surface decreased from 164.1 to 24.1 μN.The results of this study revealed the solid-liquid adhesion mechanism on the tooth groove surface,which had important theoretical and practical value for the design and manufacture of new surgical medical devices. The effects of the sub-millimeter tooth groove apex angle and tooth groove depth on wettability were studied,and the influence of microgrooves on the contact state between the droplet and sample was studied,providing insight into complex planar hydrophobic mechanisms. The results showed that the contact area between the droplet and the surface changed from an integral contact area to multiple discontinuous areas of micro-grooves,which increased the three-phase contact line between the droplet and the surface. The Wenzel model contact between the droplet and sample changed to the Cassie-Baxter model contact and remained stable. The multilevel structure reduced the surface adhesion. Compared with the tooth groove array surface with a similar vertex angle,the adhesion of the 120° multilevel structured surface decreased from 164.1 to 24.1 μN.
multilevel texturelasersuper-hydrophobicitytooth groovecontact stateadhesive force
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维普
